Ploting, Imaginary parts of complex X and/or Y arguments ignored

I have question.

I want to plot function plot(x,f(x)), but f(x) has some complex values for some values of x. When I want to plot this function, I receive report ''Imaginary parts of complex X and/or Y arguments ignored''.

How to solve this problem, because I want to plot f(x) for all values, not just real?

Thank you very much for any answer.

Regards,

Nikola

Answer 1

[Walter Roberson]

What would you like the output to look like at the f(x) that are imaginary?

plot() has not ignored any points: it has done the equivalent of

plot(x, real(f(x)))

on your behalf.

Perhaps you would like something such as

fx = f(x);
plot(x, real(fx), 'b', x, imag(fx), 'r');

[Tarun Singh]

why you have written 'b' and 'r' here?

[Walter Roberson]

'b' and 'r' are color codes, blue and red, so that the real and imaginary parts can be distinguished at a glance.

Answer 2

[Sean de Wolski]

You can either add another dimension to yuor plot (another line or plot3) and extract the imaginary parts (using imag()) or you can convert to real using abs())